Answer :
[tex]\sqrt{\frac{49 }{4}} =\frac{\sqrt{49}}{\sqrt{4}}=\frac{\sqrt{7^2}}{2^2}=\frac{7}{2}=3\frac{1}{2}[/tex]
[tex] \sqrt{ \frac{x}{y} } = \frac{ \sqrt{x} }{ \sqrt{y} } \ \ \ \ and\ \ \ x \geq 0,\ y>0\\\\-----------------\\\\ \sqrt{ \frac{49}{4} }= \frac{ \sqrt{49} }{ \sqrt{4} } = \frac{7}{2} =3 \frac{1}{2} [/tex]